Messages in this thread | | | Subject | Re: [PATCH v6 04/12] x86/smpboot.c: Don't offline CPU0 if any irq can not be migrated out of it and remove CPU0 check in smp_callin() | From | Suresh Siddha <> | Date | Thu, 17 May 2012 15:47:09 -0700 |
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On Mon, 2012-05-14 at 14:17 +0200, Ingo Molnar wrote: > * Tony Luck <tony.luck@intel.com> wrote: > > > Biggest code impact of that is the extra code to bring cpu0 > > back online using NMI instead of INIT. We can't use INIT > > because if cpu0 gets one, it just resets the whole machine :-( > > But obviously we'd like to avoid special cases where there is > > a sane way to do so. > > Could we just standardize on NMI bringup during regular bootup?
May be we can use the NMI or even better monitor/mwait based bringup to re-online an AP that is currently offline in play_dead(), specifically if we haven't lost that AP processor state because of suspend/resume event etc.
This can speed-up online if we want to use light weight online/offline of the AP's for saving power on mobile platforms.
thanks, suresh
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